Method of setting twist in threads or yarns



v March 22, 1949. T. H. STORY 2,465,130

MET OF SE ING TWIST I HREAD R YA Filed May'SO, 19

lu mi,

v n, Zia, f7@ 5 Z5 /z7d/ l A fia, ffl@ Haq 114* Fly.;

1N V EN TOR.

Arroz/wy Patented Mar. v2z, 1949 ME'monoFsE'r'rING TWIST rumanos oaYAaNs Theodore H. Story,

,Tof Delaware Merchantville, N. J., assigner to Radio Corporation ofAmerica, a corporation Application May 30, 1945, Serial No. 598,709

5 Claims. (Ci. 28-72) wound and this results in knots or the like whichhinder the free use thereof. To overcome this dimculty, it has beenproposed to set the balance or the twist by heating the yarn for from 2to 6 hours, depending upon the particular thread or yarn involved, inhumid atmospheres having a relative humidity of 70 per cent or higher.While such processing overcomes the aforementioned diiculty, it is quitetime consuming and therefore a definite limitation upon the rate ofproduction of the yarn or thread.

To increase the speed ofproduction of the yarn, it has been proposed tosubject the same to treatment in a vacuum. In general, the time requiredto set the twist is thus cut down to the order of about a half hourafter the proper vacuum has been obtained. However, a sizable amount oftime is required to create the vacuum. to say nothing of the fact thatthe high pressure vessels, seals, pumps, and other components of thevacuum systems are quite expensive.

To overcome the foregoing objections, it has been proposed heretofore toplace the yarn packages or cakes, as they are known, in wax paper orsimilar moistureproof bags or envelopes and to subject the packages orcakes to the iniluence of a high frequency electric field. This ileldvaporizes the residual moisture in the yarn (which may be of the orderof 10 per cent to 14 per cent) and establishes a humid atmosphere withinthe bag. As the yarn package -cools in the presence of the expelledvapor, the twist therein sets more or less. However, this processrequires individual handling and wrapping of each of the yarn packagesand therefore renders the process expensive, particularly for smallpackages. Moreover, the wrapping of the individual packages sometimespresents a problem.

The primary object of my present invention is to provide an improvedmethod of setting the twist or balance in yarn, thread or the like ofdielectric material which will not be subject to the above mentioneddiiculties.

More particularly, it is an object of my present invention to provide'animproved method oi setting the twist of yarns' of dielectric materialwhich will require a much shorter time than is required by prior artmethods.

It is also an object of my present invention to provide an improvedmethod of setting the twist of thread, yarn, cord, and the like whichcan be carried out at relatively low cost and in a highly efficientmanner.

In accordance with my present invention, I first subject that package ofyarn or thread to a substantially uniform high frequency electric fieldwhich rapidly heats the dielectric thread substantially uniformlythroughout until steam is generated uniformly throughout the entire yarnpackage. The package is then immediately placed in vessels or chambershaving a highly humid atmosphere for suiiicient length of time to setthetwist. These vessels or chambers may be lled with live steam, forexample. The time required to carry out the entire process will varywith the material being treated but' will, in all cases, be only about10 per cent of that required to set the twist by steam alone. Thus, forexample, in the case of rayon, the thread can be heated in about a halfminute o r a minute to 212 F. by reason of the dielectric lossesproduced in the rayon to thereby vaporize the residual moisture therein,after which the hot package may be placed in a steam room for about, 10minutes. The initial heating (that is, by means of the high frequencyelectric field) can be carried out in the open or free atmosphere, ifdesired, so that the packages need not be Wrapped or otherwise conned,while the steam heating takes place in a closed or confined vessel. Itwill be apparent,

therefore, that my present invention entirely' eliminates the need forWrapping the thread, avoids the use of a vacuum, and yet greatly reducesthe time required for the complete process.

The novel features that I consider characteristic of my invention areset forth with particularity in the appended claims. The inventionitself, however, as well as additional objects and advantages thereof,will best be understood from the following description when read inconnection with the accompanying drawing in which Figure l is a partlysectional and partly diagrammatic View of one form of twist settingapparatus for carrying out my present invention,

Figure 2 is a top plan view of a portion thereof, and

Figure 3 is a view similar to Figure 1 of a somewhat diiferent form ofapparatus for carrying out my present invention.

necessary by the Referring more particularly to the drawing whereinsimilar reference characters indicate corresponding parts throughout,there is shown a steam chamber l which is supplied with steam through aninlet pipe 3 from which the condensed moisture is withdrawn through apipe E. The chamber i includes a platform or table 'l in alignment withand immediately adjacent to an endless conveyor` or belt 9 which passesover an insulated plate il and around a pair of pulleys i3, one of whichmay be power driven. The plate II supports an electrode i 5 forcooperation with a second electrode il, both connected through atransformer l 9 to a source of high frequency electrical energy 2 l,such as a vacuum tube oscillation generator. Packages of yarn 23, whichmay be in the form of spools, bobbins, quills, cones, tubes or the like(formed by winding in a multiplicity of layers a thread or yarnconstituted by a plurality of individual filaments or strands which aretwisted together) may be placed on the belt 9 which advancesI thembetween the electrodes i5 and I1. The uniform, high frequency electricfield set up between the electrodes U5 and [Il rapidly heats thepackages 23 substantially uniformly throughout the entire length of thethread I by reason of the dielectric losses therein and causes theresidual moisture in the packages to be vaporized. Beyond the electrodesl5 and il, the belt 9 advances the packages 2t through an inlet chuteinto the vessel or chamber l which is maintained at a relative humidityof '70 per cent or more. As the packages 22 pass through the chamber l,they gradually cool and, When' they emerge through the exit chute 2l,the twist in the threads thereof have become set.

The apparatus shown in Figure 3 is similar to that shown in Figure 1.Here, however, the inlet and exit chutes 25 and 2l are omitted and thesteam chamber i is provided with inlet and outlet openings 25d and LZ'lainstead. The beit 9d in this modication is arranged to pass through theentire length of the chamber l and therefore feeds the packages 23therethrough in spaced relation to each other, whereas in Figure l theyare in contact with each other. Also, in the apparatus of Figure 3, theelectrodes i511 and i la are both within the chamber i, so that thepackages 23 are heated by radio frequency energy While they are alreadyexposed to or submerged in the humid atmosphere. As in the case of thesystem of Figure 1, the packages 22 are heated rapidly by the dielectriclosses produced therein when subjected to the high frequency electriciield, and, as they cool within the humid atmosphere. the twist in thethreads thereof becomes set.

Wherever, in this speciiication, 1l have used the terms yarn, thread"cord and the like, 1 intend these to be the equivalent of andsynonymous with each other, since my present invention is applicable toall', and whether for setting the twist or for effecting the 'balancethereof. Al though I have shown and described two forms of apparatus forcarrying out the method of my present invention, it will undoubtedly beapparent to those skilled in the art that many other ways and otherforms of apparatus are possible for this purpose. I therefore desirethat my invention shall not be limited except insofar as is made priorart and by the spirit oi the appended claims.

I claim as my invention;

region to a humid atmosphere until the twist has been set.

2. The method of setting the twist of moisture containing threadconstituted by a plurality of strands of dielectric material twistedtogether which comprises first subjecting said thread, while unconfined,to the influence of a substantially uniform, high frequency electric eldof sunicient intensity to rapidly heat said thread substantiallyuniformly by reason of the dielectric losses produced therein whereby tosubstantially uniformly expel moisture from said thread, and then, whilesaid thread is still hot, subjecting it in a confined region to a humidatmosphere unt1l the twist has been set.

3. The method of setting the twist of thread according to claim 2characterized in that said thread is subjected to said electric fieldwhile exposed to the free atmosphere.

4. The method of setting the twist of thread according to claim 2characterized in that said thread is subjected to said electric field atone location, and characterized further in that the heated thread issubstantially instantaneously thereafter transferred to another locationto be subjected to said humid atmosphere.

5. Apparatus for setting the twist of thread constituted by a pluralityof strands of vdielectric material twisted together which comprisesmeans for advancing the thread along a path successively past anunconned location and a conned location, means for subjecting saidthread to the influence of a high frequency electric field at saidunconned location, and means for subjecting said thread to humidatmosphere at said confined location.

THEODORE H. STORY.

REFERENCES CITED The following references -are of record in the file ofthis patent:

UNITED STATES PATENTS OTHER REFERENCES Daily News Record (New Yorki, May25, 1944. Page 14.

Journal of Commerce and York) May 25, 1944. Page 13.

Wall Street Journal, May 25, 1944. Page 5. Textile World, August 1944.Pages 96, 97 and Thermex High Frequency Heating. Corp. Louisville, Ky.,pages 9-11.

Commercial (New Girdler

